Chemical properties of acid salts, what are acid salts?

1. There are two sexes, which react with both acid and alkali;

2. Acid salts with weak acids.

Unstable, easy to decompose into normal salt when heated.

3. Acid salts of weak acids can be hydrolyzed.

4. Acid salts with strong acids, such as NaHSO4, are completely ionized in water and have the properties of monobasic strong acids.

Sodium bisulfate is a strong acidic salt; The strong and weak acids of high school chemistry are to be backed by back;

As far as I know, there must be only three elements in an oxygenated acid in the high school range (which is not true if you count organic acids).

Strength of oxygenated acids.

A method for judging the strength of oxygenated acids.

Rewrite oxygenated acids to:

oh) MXON form.

For example. h2co3

Rewritten to. oh)2co

The strength of oxygenated acid is judged by the value of n.

If n=0, it is a very weak acid.

As. hclo

-oh)cl

If n=1, it is a weak acid.

As. h2sio3

-oh)2sio

If n=2, it is a strong acid.

As. h2so4

oh)2so2

If n=3, it is a super acid.

As. hclo4

oh)clo3

ps: You didn't bow!

In fact, it is not difficult to get a sour salt. Not much. Let's take an example.

NaHSO4 and Na2SO4

The former is an acid salt.

The latter is positive salt.

The key is the (h) of HSO4-

Kindness. I don't know if you have seen ionization and hydrolysis. HSO4- This ion can be ionized as H+ and SO42-

Because H+ makes the solution acidic.

So you can understand it that way.

Acid salts are the presence of h (oh - this is not oh. Like NaH2PO4, it is also an acid salt.

The most important property is that they are both bisexual, and can react with both acids and bases.

2nahso4+

Ca(HCO3)2+NaOH (less) ===CaCO3+NaHCO3+H2O

Ca(HCO3)2+2NaOH (over)===CaCO3+Na2CO3+2H2O

Acid salts are defined as salts in which cations are ionized when ionized and hydrogen ions are in addition to metal ions (or ammonium), and anions are acid ions. Because cations contain hydrogen atoms that can be ionized in water, they are called "acid" salts.

However, in fact, only strong acids (such as sulfuric acid) and a small number of acid salts of strong acids (such as phosphoric acid) are acidic, and most of the acid salts of weak acids are alkaline due to the hydrolysis of anions. Salts in chemistry are divided into single salts and combined salts, single salts are divided into normal salts, acid salts, and basic salts, and combined salts are divided into compound salts and complex salts.

Chemistry:

Chemistry is a kind of natural science, mainly at the molecular and atomic levels, studying the composition, properties, structure and change laws of matter, and creating new substances (the essence is molecules that do not exist in nature). The world is made up of matter, and there are two main forms of change: chemical and physical changes (and nuclear reactions). Similar to particle physics and nuclear physics, which study the smaller scale, chemistry studies the material structure of atoms, molecules, ions (groups), chemical bonds, intermolecular forces, and other interactions.

Acid salts: salts that ionize hydrogen ions, usually the product of the partial neutralization of hydrogen ions in an acid. Common acid salts are sodium bicarbonate, potassium bisulfate, sodium dihydrogen phosphate, bicarbonate, dihydrogen phosphate, etc.

(1) Solubility in water

Generally speaking, at the same temperature, the solubility of the acid salt corresponding to the insoluble normal salt is greater than that of the normal salt, such as CaCO3 is insoluble in water, and Ca(HCO3)2 is soluble in water; The solubility of the acid salt corresponding to the soluble normal salt is smaller than that of the normal salt, such as the solubility of Na2CO3 is greater than that of NaHCO3.

(2) Reaction with alkali

Acid salts can react with alkalis, and weak acid acid salts can react with both strong acids and strong bases. The common acid acids in middle school are: HCO3, HSO3, HS, H2PO4, HPO42, etc., and the common reactive ion equation is:

hco3－+oh－=co32－+h2o

hso3－+oh－=so32－+h2o

hs－+oh－=s2－+h2o

(3) Reaction with acids

The acid salts of strong acids do not metabolize with acids. Although it is a salt, it can be used as a strong acid, and its aqueous solution has the general properties of acid, such as NaHSO4 can react with metals that are active before hydrogen to generate hydrogen; The acid salts of weak acids do not react with their corresponding acids (with the exception of HPO42) and can react with acids that are more acidic than them to form new acids and salts.

(4) Acid salt ionization and hydrolysis

Acid salts with strong acids can only be ionized and cannot be hydrolyzed; The acid salt of a weak acid can be both ionized and hydrolyzed, and the acidity and alkalinity of its aqueous solution will be determined by ionization and hydrolysis, as well as cations.

(5) Stability to heat

Generally speaking, the thermal stability of normal salts is stronger than that of acid salts, and at the same time, they are stronger than the corresponding weak acids, that is, normal salts and acid salts.

Acidic: Hydrochloric acid neutralizes with lye when dissolved in lye. Reducibility:

Hydrochloric acid is reducible and can react with some strong oxidants to release chlorine gas. Coordination: When some metal compounds are dissolved in hydrochloric acid, metal ions will be complexed with chloride ions.

In an acidic environment, alcohols can be nucleophilically substituted to form halogenated hydrocarbons.

Uses of hydrochloric acid1. Daily use.

Using the properties of hydrochloric acid that can react with insoluble alkali, daily necessities such as toilet cleaners and rust removers are prepared.

2. Analytical chemistry.

In analytical chemistry, hydrochloric acid is generally used to determine the concentration of alkali with acid. Titration with a strong acid can make the endpoint more obvious and thus obtain more accurate results. At 1 standard atmosphere, hydrochloric acid can be composed of a constant boiling solution, which is often used as a reference in quantitative analysis at a certain atmospheric pressure.

Its concentration at constant boiling changes with air pressure.

3. Pickling steel.

One of the most important uses of hydrochloric acid is to pickle steel. Before the subsequent treatment of iron or steel (extrusion, rolling, galvanization, etc.), hydrochloric acid can be used to react the rust or iron oxide on the surface. Carbon steel is usually cleaned with a hydrochloric acid solution at a concentration of 18% as a pickling agent.

1.Acidic, can discolor indicators, such as litmus, pH test paper.

Neutralizes bases, and reacts with basic oxides.

Hydrogen ions are provided in some reactions.

2.Oxidizing, mainly dry oak is reflected in hydrogen ions, Fe + 2HCl (concentrated or dilute) = = FeCl2 + H2

3.Reducibility, 2kmNO4 + 16HCl (concentrated) ==2KCl + 5Cl2 + 2mnCl2 + 8H2O

4.It can react with some salts, such as the qualitative reaction of silver nitrate.

Note: The oxidizing properties of hydrochloric acid are reflected in hydrogen, chlorine is the lowest price, only reducible, like this reaction 6HCl + Fe2O3 ==2FeCl3 + 3H2O shows that the strong oxidation of hydrochloric acid is unfounded, can only reflect its acidity. In addition, concentrated hydrochloric acid has strong reducing property and non-careful oxidation.

Hydrochloric acid is reducible: mNO2+4HCl==mnCl2+Cl2+2H2O

Concentrated hydrochloric acid has strong oxidizing properties: 6HCl + Fe2O3 ==2FeCl3 + 3H2O